Removal of Acrosomal Membrane from Sperm Head Improves Development of Rat Zygotes Derived from Intracytoplasmic Sperm Injection

Purpose This study was performed to investigate whether removal of cholesterol from the plasma membrane and collapse of the acrosome can prevent structural chromosome aberrations of paternal origin in mouse zygotes produced by intracytoplasmic sperm injection (ICSI). Methods Mouse spermatozoa were treated with methyl-β-cyclodextrin (MβCD) to remove cholesterol from the plasma membrane and with calcium ionophore A23187 to collapse the acrosome. Chromosomes of zygotes derived from MβCD-and ionophore-treated spermatozoa were analyzed at the first mitotic metaphase. Results Both chemical agents effectively induced the acrosome reaction. Incidence of structural chromosome aberrations in ICSI zygotes derived from MβCD-treated spermatozoa was similar to that in zygotes produced by in vitro fertilization (IVF) with the same spermatozoa, but significantly lower compared to ICSI zygotes derived from acrosome-intact spermatozoa. Chromosome aberration rates in ICSI zygotes derived from ionophore-treated spermatozoa were evidently high compared to IVF zygotes. Conclusions Induction of the acrosome reaction through cholesterol efflux by MβCD can prevent chromosome aberrations of paternal origin, while use of ionophore to induce the acrosome reaction exerts detrimental effect on paternal chromosomes in ICSI zygotes.

Section: Introductionmentioning

confidence: 97%

Chromosome analysis of mouse zygotes produced by intracytoplasmic injection of spermatozoa exposed to acrosome reaction inducing agents methyl-β-cyclodextrin and calcium ionophore A23187

Tateno

2010

“…2b). Similarly,in homologous rat ICSI, the timing of pronuclear formation using TX or lysolecithin treated sperm was significantly accelerated compared to control sperm [25]. In the mouse, homologous ICSI of TX treated sperm yielded no difference in fertilization, blastocyst, implantation and live birth rates compared to control sperm [36].…”

Section: Discussionmentioning

confidence: 93%

“…Regardless, live offspring have been born using ICSI in a variety of species, including humans and mice [23]. However, existing reports on higher incidence of chromosome aberrations [24] and lower developmental potentials [25,26] in embryos produced by ICSI indicate that further evaluations on the effects of the incorporation of the acrosome into the oocyte are needed.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of human male pronuclear development in a heterologous ICSI model

Jones

Mudrak

Zalensky

2010

Purpose To evaluate human sperm nuclear chromatin decondensation in a heterologous ICSI system using hamster ova injected with human sperm. Materials and methods Frozen hamster oocytes were injected with Triton X-100 treated sperm and fixed at different time points post ICSI. Oocytes injected with nontreated sperm served as controls. Male pronuclear decondensation was evaluated after staining with DAPI. Results Sperm cells with partially destroyed membranes and depletion of the acrosome decondense more rapidly and to a greater extent than membrane/acrosome intact cells. Marked variability in pronuclear size was observed for any time point post ICSI, which most probably reflects the heterogeneity in the mature human sperm population. Conclusion Remodeling of male gamete nuclei in this heterologous ICSI mimics events that occur during natural fertilization in humans and therefore this approach may be used for studies of human sperm chromosomes transformations.

“…Several reports showed higher efficiency in mouse and human ICSI following removal of the acrosomal vesicle [18,29,32], which rested on the assumption that its hydrolytic enzymes could harm the oocytes [25,37]. Notwithstanding that ionomycin induces acrosomal reaction (as suggested by Rotem et al [26] and confirmed in our experiments), we reached the same blastocyst rate by injecting piezo-pulsed spermatozoa pretreated both with and without ionomycin (PPS: 15.6 % vs. PPS-I: 15.5 %).…”

Section: Discussionmentioning

confidence: 99%

Plasma membrane and acrosome loss before ICSI is required for sheep embryonic development

Anzalone

Iuso

Czernik

et al. 2016

Purpose This study aims to determine if the integrity of the sperm plasma membrane and acrosome vesicle could be limiting factors in sheep intracytoplasmic sperm injection (ICSI). Methods Prior to in vitro fertilization (IVF) or ICSI, the oocytes were subjected to in vitro maturation (IVM) for 24 h. First, to evaluate the need of artificial activation for ovine ICSI, 226 oocytes were injected with intact spermatozoa (IS), from which 125 were activated by incubation in ionomycin and 101 were cultured without activation. Next, spermatozoa were mechanically (by piezo-electrical pulses) and/or chemically (by ionomycin/Triton X-100) treated to break membranes and acrosomes and were injected into oocytes, grouped as follows: (i) piezo-pulsed spermatozoa (PPS), (ii) PPS pre-treated with ionomycin (PPS-I), (iii) PPS pre-treated with Triton X-100 (PPS-T), and (iv) intact and untreated spermatozoa as a control (CTR-IS). Results No differences were observed in the zygote/cleavage/ blastocyst rate between chemically activated and nonactivated oocytes (50 vs. 45 %, 11.6 vs. 10.1 %; 1.8 vs. 1.1 %, respectively), after ICSI with CTR-IS. Injection of PPS compared to CTR-IS increased the proportion of zygotes and blastocysts (84.6 vs. 45 %, p < 0.01; 15.5 vs. 1.1 %, p < 0.0001, respectively). Moreover, the percentage of PPSderived blastocysts was not significantly different from that obtained by conventional IVF (15.5 vs. 20.2 %). The ICSI blastocysts' development was also improved with PPS pretreated with ionomycin (15.6 %), but was completely impeded with PPS pre-treated with Triton X-100 (0 %). Conclusion Our findings confirm that ICSI with spermatozoa whose plasma membrane and acrosome have been mechanically damaged substantially improves embryonic development until the blastocyst stage.